Carbon Calculator Activity
The Carbon Sequestration Value of Trees
We know that plants sequester large sums of carbon in themselves. They are able to do
this since, on average, photosynthesis produces more sugar than what is needed by the plant
during its respiration phase. As long as the plant is alive, it will continue to take carbon dioxide
out of the air. However, we also know that a plant will return all of that carbon back into the
atmosphere after it dies if the wood is burned or allowed to decay.
In this activity, you are going to investigate what effect mankind has on the carbon cycle.
In particular, we are going to estimate the amount of carbon dioxide that each one of us is
responsible for emitting each year. This analysis is going to study only those day-to-day
activities that emit carbon dioxide, and not look at the unique events that we have that also emit
carbon dioxide (like bulldozing a forest and grinding up the trees). Our modern way of life relies
heavily on the emission of carbon. When we think about this, we often limit ourselves to the use
of automobiles and trucks and a few industrial processes. We understand that when we burn the
gasoline in our engines, we are oxidizing the fuel and creating carbon dioxide. However, there
are other activities in our life that also emit CO2, even though we do not see the oxidation. When
we use electricity, we are also emitting carbon dioxide. The majority of the electricity created in
the U.S. is derived from burning natural gas or coal. We also emit CO2 when we heat and cool
our homes, since this requires the use of electricity or the burning of natural gas, propane,
heating oil, or wood. Even our creation of garbage releases carbon in the environment. If this
garbage is put into a landfill, it decays and puts CO2 and methane (CH4) back into the
atmosphere. If it is recycled, energy of some form will be used to accomplish this, emitting CO2
in the process.
Calculating Your Emissions of Carbon Dioxide Overview:
So how much carbon dioxide is emitted to the atmosphere through your daily activities?
To answer this question, you will use an online Carbon Footprint Calculator. These calculators
add up the carbon dioxide produced by your different personal activities, and provide you with
an estimate of your annual carbon dioxide emissions.
1. How many kg/pounds of carbon dioxide are emitted by you each year?
2. Did this amount surprise you? Why or why not?
3. What activities or habits do you think you could change the most easily to reduce your
emissions each year?
Calculating Tree Sequestration Requirement:
(This step is best completed following the “How Big is Your Tree” activity)
Using the Carbon Stored in Trees by Size-Table, you will calculate the number of trees
required to sequester (store) the amount of carbon that you emit.
1. With the class, go outside and select a tree to compare your results to. Preferably you
should use the tree that you used in the How Big is Your Tree activity.
2. Using the measurements for that tree, how much carbon would that tree store? (Round to
the nearest tree size)
3. How many trees would be required to sequester all of the carbon that you produce in a
single year?
4. Let’s make the assumption that you have been emitting the same amount of carbon your
whole life (not a very good assumption, as you didn’t need as much when you were a
little child, but it still shows a pretty cool concept). Multiply your age by the number of
trees required for one year of your emissions. How many trees is that? (This is the
number of trees that would need to be grown to that size to just make up for your carbon
emissions!)
5. Assuming that you emit an average amount for every American, and knowing that there
are approximately 300 million Americans, how many of your trees would be required to
make up for your one year’s worth of emissions?
6. Take a look at your answer to the previous question. Discuss what this number means to
you in terms of our ability to store all of the carbon that we emit each year. Do you think
we can keep up with emissions just by planting trees? What would be some problems of
using the planting of trees as the only answer to cleaning up all the carbon dioxide we
emit?